Non-destructive evaluation of functional fabrics

Abstract

The present invention provides a method for determining the functionality remaining in a functional fabric, the method comprising the steps of: providing a used functional fabric having a known original functionality, a current wear, and a current unknown functionality, providing a light source, providing a detector, optically measuring the current wear using the light source and the detector, and evaluating the current unknown functionality using a correlation that expresses the current unknown functionality as a function of the current wear, optionally the detector further comprises a digital camera, and wherein the method further comprises the step of: obtaining a magnified image of the functional fabric and quantifying the fractal dimension using a box-method fractal analysis on the image. The method may be applied the insecticide treated fabrics.

Description

BACKGROUND[0001]Functional fabrics may be produced or modified to provide a specific function. Herein we define a functional fabric as a fabric that is intended to provide a specific function. For example, functional fabrics may be used for water-repellent clothing, permanent press clothing, antimicrobial clothing, and clothing or bednets treated to kill or repel biting arthropods. Functional fabrics may have an additive when they are produced or may have an additive incorporated after they are produced. Functional fabrics can also be treated to produce or enhance the function; such a fabric will be referred to herein as a treated fabric. In a functional fabric the fabric and additive or treatment act together to produce the desired effect.[0002]In use, functional fabrics can lose part or all of their function due to exposure to the environment, laundering, wear and abrasion. In a used functional fabric, it is desirable to determine the functionality remaining, so the user can decid...

AI Technical Summary

Problems solved by technology

In use, functional fabrics can lose part or all of their function due to exposure to the environment, laundering, wear and abrasion.

Such methods are often expensive, time-consuming, may damage the fabric or garment, and may require resources that are not readily available.

Such methods can require reagents and analytical instruments that are not readily available in the field, may be expensive and time-consuming, and may damage the fabric or garment.

Further, such methods only confirm that a specific additive is present, not that functional fabric performs its function.

For example, the insecticide on a treated garment may be present, as determined by chemical analysis, but may not perform the desired function because it is not biologically available, or the fabric may be so worn that it does not form an adequate physical barrier.

Functional fabrics may suffer loss of function during normal use due to fabric wear and due to loss of the additive.

Laundering may cause loss of function and is also a source of fabric wear.

However, particularly in the case of water-repellent or insect-protective fabrics, if the functionality is not present everywhere in the fabric, then the function is compromised.

For example, if a section of a garment is not water-repellent the wearer will get wet in that location.

More seriously, if a section of an insect-protective garment does not retain its functionality, then the user could get bitten in that location, potentially acquiring a disease.

However, it has been found that uniforms worn in the field lose activity faster than predicted by the number of wash cycles they have been through.

Furthermore, some uniforms showed negative bite protection; in those cases, the bite protection afforded by the treated, field-worn uniform was less than that provided by a new, untreated uniform.

Further, as wear breaks down the uniform fibers, water can more easily penetrate and insects (including mosquitoes) can more easily bite the wearer through the fabric.

The above methods rest on chemical analysis, which can be very specific to the additive (for example, a pyrethroid containing a cyano group); other additives may not respond to the analytical method, requiring development of new chemistry.

These references contain at least one of the following limitations in regard to evaluating functional fabrics: inability to assay functionality non-destructively; requires reagents, solvents or specialized equipment that are not readily available; requires direct measurement of the function, for example live insect tests; is expensive, is inconvenient; or does not utilize fractal analysis to assay functionality.

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